Guideline for Application and Use of High Performance Concrete. in Projects of Ministry of Transportation Kingdom of Saudi Arabia

Transcription

1 Guideline for Application and Use of High Performance Concrete in Projects of Ministry of Transportation Kingdom of Saudi Arabia Rajab 1431 H July 2010

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5 Preface By H.E.Dr.Jobarah bin Eid Al-Suraisry Minister of Transport Kingdom of Saudi Arabia achieved a great development in Highway and construction fields during a short period of time, and it has an advanced Highway networks matching with the finest Highway networks in the world comparable in its structure and bridges. Concrete structures as bridges and culverts represent vitally essential part of network elements. Quality of concrete in Saudi Arabia was raised because of using ready-mixed concrete. This development would achieved for the grace of Allah, and unlimited support from the Government of the Custodian of the Tow Holy Mosques King Abdullah bin Abdulaziz Al-Saud and his royal highness Prince Sultan bin Abdulaziz Al-Saud. Using of ready-mixed concrete in Highway projects and bridges gives a great impact in raising the level of concrete work and also it gives possiabilty for using deferent types of cement and producing different types of concrete (from ordinary concrete to high strength concrete and high performance concrete),although the Kingdom environment characterized by cruel and adverse effect on concrete structures. The process of design and implementation of concrete bridges are still based primarily on the basis of their ability to 5

6 transfer loads only, without any regard to the durability of concrete and its ability to resist the elements of nature and the environment. Accordingly, this is the time to activate the role of «Durability Based Approach» in the three stages of construction: design, implementation, and maintenance. Among the most important ways to activate the trend towards of durability and resistance to time is the use of high-performance concrete, which will be covered in this guideline. I hope that this guideline helps all persons interested in High performance concrete implementation and design. With best Wishes of success,,,,,,,, 6

7 Preface By H.E Eng. Abdullah bin Abdul-rahman Al- Mogbel Deputy Minister of Transport For Road Highway and bridge projects in the Kingdom of Saudi Arabia are the biggest and the more numerous in the Arab world. Ministry cares by raising the efficiency of bridges not only in terms of transfer the loads from vehicles, but also in terms of bridges resistance to the environmental and climatic conditions. Ministry has concerned with research and studies deal with this area and contracted with one of the local consultants to cooperate in preparing the study on the application of the system in high-performance concrete in projects of Ministry of Transport to take into account the durability and ( resistance ) factors. High-performance concrete has several definitions, and the definition of HPC according to Strategic Highway Research-SHRP can be summarized as follows: A highest proportion of water to cement (W/C) = 0.35 Minimum durability factor is 80% as measured in s (ASTM C666) Minimum Compressive Strength for Concrete. The Federal Highway Administration (FHWA) has proposed a definition of high-performance concrete using concrete in the performance at latest 7

8 age. The proposed definition depends on four factors for the durability and four factors for the resistance of concrete. In addition, American Concrete Institute ( ACI) has been defined high-performance concrete as a concrete, given the special requirements in the performance and consistency that can not be obtained always from using regular components and regular method of mixing and treatment as usual, and these requirements can be summarized as follows: Easy for casting and compaction without any effect on concrete strength. High resistance at late ages. High strength. Volume stability. Long life at hard climate conditions. The bridge engineers should put into their consideration when determining the definition of high-performance concrete all the factors of durability and resistance, because the performance of concrete will be measured by several factors and linked to their respective concrete resistance and determining the performance of each factor by standard tests. In economic side, the cost per cubic meter of high-performance concrete is more than the cost per cubic meter of normal concrete because the highperformance concrete, contains higher amounts of cement and other cement materials and quantities of the highest additions of concrete plasticizers, plasticizers. But it must be known that concrete is only one of the component used in concrete construction. The total cost of the bridges depends on several 8

9 other factors, including the implementation period and the amount of concrete used, which could be much reduced in case of using high-performance concrete. As the pressure resistance of the concrete have the greatest influence in the design and the tensile strength has a secondary effect on the design, the use of concrete to resist high pressure may lead to increase bridges spans up to 145%, which are used by concrete with normal resistance, and the use of concretes with high resistance has led to use a cable diameter of 15.2 mm. This guide has been taken into account the definition of the properties of high performance concrete, different grades of HPC, specifications of the various constituent materials available in the Kingdom and the way of design, and the standard tests for quality control of high-performance concrete in accordance with the conditions of the Kingdom. The ministry advises all contractors and consultants who are associated with its projects to abide by the steps and instructions given in this manual in pursuit of the public interest. 9

10 Acknowledgement The Ministry of Transport (MOT) would like to thank all those who contributed to the preparation and production of this Manual in its present shape. The effort made in compiling the technical material and ultimately producing this publication is greatly appreciated by the Ministry s officials. In this context special thanks go to Eng. Mohamed bin Shafiq Azam the General Director of Material & Research Dept. and each of Eng. Alabbas Ahmed AL Hazmi, and Eng. Salman Mohamed Al-Dahmash from General Directorate of Material & Research. The Ministry also grateful to Advanced Engineering Center represented by Dr. Ibrahim Al-Dubabe, and Eng. Mohamed mahmoud Refaie for the efforts and effrctive contribution to the prepartion of this study. In addithion, The Ministry thanks Shibh Al Jazera for limited contracting Company especially Eng. Abdurrahman Mohamed Mokhtar for his efforts and cooperation in practical part of this study and participation in reviewing the Manual. The company has shown interest and dedication to success this work, as usual the company and its employees in the initiative in all that would achieve progress in the Highway industry in the Kingdom. 10

11 Table of Contents Statement Page No. Part 1: Introduction 1.1 Preface High Performance Concrete Properties High Performance Concrete Grades 12 Part 2: Specifications of HPC Components 2.1 Cement Supplementary Cement Materials Coarse Aggregates Fine Aggregates Admixtures Water 19 Part 3: Mix Design 3.1 Mix Design Steps and Affecting Factors Mix Design Examples 26 Part 4: Testing and Quality Control 4.1 High Performance Concrete Tests Quality Control of High Performance Concrete 30 11

12 Part (1) : Introduction 1-1 Preface : The high-performance concrete, which have compressive strength equal ( 65 MPa) considers as one of the standard concretes used in precast concrete, post-tension concrete, or pre-stressed concrete in the bridges. In addition, using of concrete with high grade (65 MPa) will save in quantities of concrete used by the 25-40% compared with a regular concrete grade (30 MPa). It also saves in the construction time. Consequently, the use of highperformance concrete is considered economically as a result of the provision in the materials used and reduces the construction period and transportation and installation expenses. 1-2 High Performance Concrete Properties : The high-performance concrete is a concrete with developed properties to fit certain uses and certain climatic conditions, and it is characterized by the following: Easy Casting. Compacted without segregation of its components. High compressive strength in the early ages. High mechanicals properties at late ages. Low permeability. High durability. Low volumetric changes. High resistance for abrasion. Long life with severe climatic conditions. 1-3 High Performance Concrete Grades : There are eight factors able to determine the high performance concrete grades as shown in Table (1): Durability measured by freezing and thawing degrees. Resistance to scaling. Abrasion resistance. Chloride penetration resistance. Compressive strength. Modulus of Elasticity. 12

13 Shrinkage. Creeping. There are three factors to determine high performance concrete grades for Saudi Arabia climatic conditions : Abrasion resistance. Chloride penetration resistance. Compressive strength. Table No.(1) Different grades for High performance concrete Properties Resistance of Concrete to Rapid Freezing and Thawing Standard Method of Test AASHTO T 161 ASTM C 666 proc.a High performance concrete grades according to FHWA % - 80% 80% Resistance to scaling after 50 cycles ASTM C672 4,5 2,3 0,1 Abrasion resistance (avg. abrasion thickness mm) ASTM C > Chloride penetration resistance. Compressive strength (MPa) AASHTO T277 ASTM C1202 AASHTO T22 ASTM C MPa MPa MPa 97 MPa Modulus of Elasticity (GPa) ASTM C GPa GPa 50 GPa Shrinkage ASTM C

14 Part (2): Specifications of High Performance Concrete Components 2-1 Cement First: Types of cement that can be used in High performance concrete: There are many factories in Saudi Arabia and can be divided according to their presence in the market as following: Western area: Al Arabia cement, Tabouk cement, Yanbu cement, and Tohama Factory cement. Eastern area: Eastern area cement, Saudi cement company(alhafouf cement) Central area: Al yamama cement company, Al Riyadh cement company. Northern area: Al Qasssim cement company. Southern area: Southern area cement (Tohama cement Factory) Second: Specifications of cement used in High performance concrete: The compressive strength of cement used in HPC should not be less than 45 N/mm2 after 28 days. Cement to be used shall confirm to the Saudi standard specification No.143/ 1979 for (Ordinary Portland Cement), and Saudi standard specification No. 570/ 1992 for (Sulfate Resistant Cement). 2-2 Supplementary Cement Materials First: Types of Supplementary cement materials that can be used in High performance concrete: Supplementary cement materials are an important materials used in high performance concrete because of their impact on the performance and durability of concrete as it is also used to obtain high compressive strength. These supplementary materials such as: Silica Fume. Fly Ash. Blast Furnace Slag. 14

15 Second: Specifications of Supplementary cement materials used in High performance concrete: A) Silica Fume: It is a secondary product from Silicon factories and very fine material. Silica Fume shall confirm to the ASTM C1240 specification as shown in Table No. (2). Table No.(2) Silica Fume Specifications according to ASTM C1240 ASTM C1240 Specifications Silica dioxide content (SiO2) % (LOI)% Specific Surface Area (m2/gm) Moisture Content (%) % Retained on Sieve (45 micron) by washing Not less than 85% Not more than 6% Not less than 15 (m2/gm) Not more than 3% Not more than 5% Note: Preferred to use silica fume in Eastern Area of Saudi Arabia to increase the resistance and prevent the corrosion of reinforcement in concrete structures and to increase their compressive strength. B) Fly Ash: It is a secondary product produced in power plant running by coal, and its quality varies from one plant to another and even in the same plant. Fly Ash shall confirm to the ASTM C618. Loss of Ignition (LOI) shall be less than 3%. Calcium Oxide content (CaO) shall be very low as possible (Preferably less than 5%). 15

16 C) Slag: It is a secondary product produced in high furnace factories. Slag is added by 25% to 70% of cement weight. Slag shall confirm to the ASTM C Coarse Aggregate First: Geographical Map of Coarse Aggregate in Saudi Arabia: There are several sources of Coarse Aggregate in Saudi Arabia like Natural Gravel, Crushed Limestone, Crushed Basalt, and different types of igneous rocks. They are distributed as follows; Northern Area: Natural gravel, crushed limestone and crushed basalt. Central Area: Crushed limestone Southern Area: Natural gravel and crushed basalt. Western Area: Natural gravel, crushed basalt, and crushed granite. Eastern Area: Crushed limestone Second: Specifications of Coarse Aggregate: Using small size of Coarse Aggregate gives high compressive strength, however, using largest size of Coarse Aggregate which can provide required strength is preferable, because of its great influence to increase Modules of Elasticity, and reduce shrinkage and creep of concrete. Coarse Aggregate used in High performance concrete shall confirm to (MOT General Specification November 1998 Part 5 Item No ) which has the following characteristics: Maximum Nominal Size = 19 mm max. Sodium Sulfate soundness, MRDTM 311, 5 cycles, Percent Loss shall be maximum of 10%. LA Abrasion, MRDTM 309, Percent Loss shall be maximum 20% for Crushed Basalt, and 30% for Crushed Limestone. Flat & Elongated Particles shall be maximum 10%. Clay Lumps and Friable Particles, AASHTO T 12, and MRDTM 312 shall be 1% max. Absorption shall be maximum 2% for crushed Basalt, and 2.5% for 16

17 Crushed Limestone. Percentage of total chloride ion (MRDTM 319) shall be maximum 0.04%. Specific Gravity shall be 2.5 min. Coarse Aggregate should be inert and not reacting with alkali according to the specification C-289 supported with the specification C-227 of ASTM. Coarse Aggregate shall confirm to requirement of Grade (c) or Grade (D) according to (MRDTM 204). 2-4 Fine aggregate First: Geographical distribution of Fine aggregate in Saudi Arabia: There are several sources of Fine Aggregate in Saudi Arabia like natural coarse sand in Western area, Southern area, and some locations in Northern area. In case where there is Dune Sand, it shall be mixed with crushed fine aggregate as used in Eastern area, Northern area, and Central area. Second: Specifications of Fine Aggregate: Fine Aggregate to be use in High performance concrete, shall has fine modulus between (2.5) & (3.2). Usually, Natural Crushed Sand gives fine modulus equal 2.5 &3.2. Dune sand should be mixed with crushed sand from crusher to give fine modulus equal to the above mentioned limits. Specifications of fine aggregate can be summarized as following: Fine Modulus shall be between 2.5 and 3.2. Clay Lumps and Friable Particles, AASHTO T 12, and MRDTM 312 shall be less than 1%. Total chloride ion content (MRDTM 319) shall be less than 0.05%. Fine Aggregate should be inert and not reacting with alkali according to the specification C-289 supported with the specification C-227 of ASTM. Fine Aggregate shall confirm to requirement of gradation shown in Table No. (3). 17

18 Table (3) Gradation limits for Fine Aggregate Sieve Size (3 / 8) 9.5 mm NO mm NO mm (NO mm NO mm NO mm % Pass Admixtures First: Definition: Admixtures are known as other materials than aggregate, water, and cement added to concrete to improve its properties in different conditions as following: Improving casting and finishing. Improving workability. Increasing compression strength. Improving general appearance. Improving pumping operation. Second: Types of Admixtures The following admixtures can be used for high performance concrete works ; 1. Water reducing admixtures 2. Plasticizers 3. Super-plasticizers. 4. Setting retardation admixtures. 5. Air entraining admixtures. 6. Setting acceleration admixtures. Third: Admixtures Specifications Admixtures shall confirm to type (F) and type (G) of ASTM C494 specifications or type (F) and type (G) of AASHTO M194 specifications. 18

19 Admixtures used is preferably to be in the range between 1% & 2% of cement weight or by a rate ranging from 1 liter to 2 liter per 100 Kg cement. The maximum dosage of admixtures shall be 3% of the weight of the cement or according to manufacturer`s technical bulletins. 2-6 Water Water used in High performance concrete shall confirm to (Part 5, Item No MOT General Specifications November 1998). Water shall not contain more than 500 PPM of chloride ions, and not more than 1000 PPM of sulfates if it is checked by (MRDTM 514). In all cases the salts in water used in high performance concrete shall not affect its compression strength. 19

20 Part ( 3 ) : Mix Design 3-1 Mix Design Steps and Affecting Factors Selection of mix proportions for High performance concrete can be summarized in the following steps. Step No. (1): Selection of workability & Compressive strength: High workability is one of the important properties of High Performance Concrete. In this case; it is prefer to measure the diameter of concrete flow by Slump Flow instead of Slump. Slump Flow shall not be less than 500 mm. For design compressive strength, it can be calculated by using equation No.(1) Fcr = 0.9 Fc S (1) (Fcr): Design Compressive Strength of concrete (Fc): Characteristic Compressive strength of concrete (S) : Standard Division If The data of the standard division is not available, Equation No. (2) can be used to determine Design Compressive Strength. Fcr = Fc + 10 MPa (2) It is known that Compressive Strength of Concrete after 56 days and 90 days is higher than compressive strength after 28 days, this is noticeable in the concrete containing Fly Ash and Slag but it is not the same for the concrete containing Silica Fume. Compressive Strength required at later ages should be used in the test to obtain economic mixes because the selection of cement materials content depends on the required compressive strength at the age of test. 20

21 Step No. (2): Selection Coarse Aggregate Size: (ACI 318) provided that the Maximum Nominal Size for Coarse Aggregate shall be not more than (1 /5) smallest distance between the forms and shall not more than (1 /3) of Slab thickness or (3 /4) of distance between reinforcing bars. As mentioned previously, High Compressive Strength depends on Coarse Aggregate size. Generally, selection of coarse aggregate size can be according to the following: Concrete with Compressive Strength less than 62 Mpa: Use NMS (19 mm 25 mm). Concrete with Compressive Strength more than 62 Mpa: Use NMS (12.5 mm 19 mm). Step No. (3): Selection Coarse Aggregate Proportion: Table No.(4) shows the recommended volume of Coarse Aggregate as a percent of Concrete volume for each MNS in case of using Fine aggregate with Fine Modulus equal Table No.(4) Recommended Coarse Aggregate volume for different MNS MNS (mm) 25mm 19mm 12.5mm 9.5mm Standard Volume of Coarse Aggregate as a portion of Concrete Volume After determining the coarse aggregate volume, the weight of coarse aggregate can be calculated by using equation NO. (3) Weight of coarse aggregate = Standard volume of coarse aggregate from Table (4) X Dry Density (3) 21

22 Step No. (4): Calculation of Water Content and Air Content in Mix: Water content used in mix depends on required degree of workability degree and the volume, shape, and gradation of coarse aggregate. Also, it depends on cement quantity and admixture type and content. Table No. (5) shows the estimated water content which must be confirmed by conducting a trial mixtures. Table No. (5) Estimated Water Content and Air Contents at Air voids 35% in Fine aggregate Slump flow (mm) 25 Coarse Aggregate size (mm) mm mm mm Flow Concrete Air Entrainment 1.5% 2% 2.5% 3% Note: Water Content determined from Table No. (5) by considering that air voids in fine aggregate = 35% Air voids in Fine Aggregate can be calculated by using equation No.(4) Air Voids in Fine Aggregates (%) = 1 (Dry Density / Specific Gravity) X 100 (4) If Air Voids is not equal 35%, Water Content should be corrected by using equation No. (5) Corrected Water Content = Water Content from table (5) X (Air voids in fine aggregate calculated / 35) (5) 22

23 Note: Water Content at table No.(5) for any mix can be reduced by 30%, If Super-plasticizers) type (G &F) are used. Step No. (5): Selection of Water/Cement Ratio (W/C): Compressive Strength of Concrete depends on water cement ratio (W/C) or water cementitious materials ratio (W/C+P). In addition, workability of concrete depends also on the water cement ratio. Table No.(6) is used to select (W/C+P) for compressive strength after 28 days or 56 days as a function of coarse aggregate size. Table No. (6) Recommended Maximum (W/C+ P) (W/C+P) Compressive Strength (Mpa) Coarse Aggregate Size 25 mm 19 mm 12.5 mm 9.5 mm After 28 days After 56 days After 28 days After 56 days After 28 days After 56 days After 28 days After 56 days After 28 days After 56 days After 28 days After 56 days

24 Step No. (6): Calculation of Cement Materials Content: Required cement weight can be calculated according to equation No. (6) Cement Content = Water Content from step No. (4) / (W/C+P) from step No.(5) (6) Step No. (7): Calculation of Mix Ratio: In case of using Cement only without any supplementary cementitious materials, weight of cement equal cement content determined from step No. (6). Then by using absolute volume method,sand or Fine Aggregate content in one cubic meter of mix can be calculated according to equation No. (7). C/γc + W/γw + G/γg + S/γs + %air content x 1000 = 1000 L (7) Step No. (8): Calculation of Mix Ratio in case of using Supplementary Cement Materials: In case of using Fly Ash, it will be used by proportion between (15%- 35%) of cement weight according to Fly Ash type. In Case of Using Silica Fume, It will be used by pro portion between (5% - 15%) of cement weight, but prevailing rate is 10% of cement weight. In case of using Blast Furnace Slag, It will be use by proportion between (30% - 70%) of cement weight. After determining the rate of Supplementary Cement Materials, Weight of these materials can be calculated by multiplying the used rate by require cement materials weight calculated from equation No.(6) Volume of any Supplementary material (Vp)= (P/ γp) Weight of Fine aggregate can be calculated from equation No.(7) after adding (P/ γp). 24

25 Step No. (9): Trial mixes: After determining quantities of different materials used in concrete mix from step (1) up to step (8), and running different trial mixes to measure workability and strength of concrete mix, fine aggregates, coarse aggregate, water content will be modified. Trial mixes are considered successfully, if a homogenous mix is obtained and can be used to cast the equivalent number of samples used to measure the strength. Step No. (10): Modifying and adjustment mix proportions: If the required properties of concrete are not achieved, it is necessary to adjust mix proportions as following steps to get the required workability. If the flow of concrete is not achieved during trial mix, water content and cement content shall be increased with keeping a constant W/C ratio. Then other component contents shall be modified. Also, dosage of admixtures shall be modified to obtain the required workability. The coarse aggregate content shall be decreased if a coarse mix is obtained and consequently fine aggregate content shall be increased. Step No. (11): Choosing the optimal mix proportions: After trial mixes and adjustment of mix proportions are finished and achieved required workability and required strength, cylinder samples for measuring compressive strength will be prepared in the field conditions to check the suitability of the mix proportions to the site condition. 25

26 3-2 Mix Design Examples (A): Example without using Supplementary Cement Materials: It is required to design High Performance Concrete mix to use in a bridge in central area with compressive strength= 60 MPa after 28 day, and by using available materials in this area : Ordinary Portland cement from Saudi Cement Company (Al- Hafof Factory). Fine Aggregate consists of dune sand and crushed sand mixed with proportions = 33% &76% respectively. Fine aggregate has a fine modulus = 2.7, specific gravity = 2.57, and absorption = 1.67% Coarse Aggregate is crushed limestone with MNS=12.5 mm. It has specific gravity =2.55, absorption = 1.93%, and dry density = 1549 Kg/m3 Step No. (1): Selection of Slump Flow & Compressive strength: Choosing Slump Flow to gives flow concrete by using 2% Super-plasticizer of cement weight. No Available data about standard division, then; Fcr = = 70 MPa Step No. (2): Selection Coarse Aggregate Size: For High Performance Concrete with Compressive Strength = 70 Mpa, NMS for Coarse aggregate = 12.5 mm Step No. (3): Selection Coarse Aggregate Proportion: From Table No.(4), the recommended volume of Coarse Aggregate as a percent of concrete volume for MNS = 12.5 mm equal 0.68 m3. Weight of Coarse Aggregate = 0.68 X 1549 = 1053 Kg 26

27 Step No. (4): Calculation of Water Content and Air Content: From table No.(5) Estimated Water Content at Slump (50mm) & MNS of coarse aggregate (12.5mm) is equal 196 Liter and air entrainment = 2.5 % Step No. (5): Selection of (W/C): From Table No.( 6) (W/C+P) at Compressive Strength = 70 MPa after 28 days is equal 0.32 Step No. (6): Calculation of Cement Materials Content: using 2% Super-plasticizer of cement weight reduced water content by 20% Water Content = 196 X 80% = 157 Liter. (W/C+P) Weight = 157 / 0.32 = 490 Kg/m3 Step No. (7): Calculation of Mix Ratio: By using absolute volume method, Fine aggregate Weight can be determined C/γc + W/γw + G/γg + S/γs + % air content x 1000 = 1000 L 490 / / / S/ x 1000 = S + 25 = S = = 250 S = 250 /0.389 = 643 kg From the above procedures, Mix proportions can be given in the following Table. Table No.(7) Mix component in kg for 1m3 High Performance Concrete Cement Fly Ash Silica Fume Slag Fine Agg.(kg) Coarse Agg.(kg) Water Admixture

28 After running trial mixes, If mix is coarse, sand weight can be increased, the weight of coarse aggregate shall be adjusted. (B): Example with using Silica Fume: If silica fume is used in mix and its content is 10% of cement weight. Silica Fume Weight = 49 Kg / m3 Cement weight = = 441 Kg/m3 Water Content = 157 Kg/m3 Coarse Aggregate Weight = 1053 Kg/m3 Fine Aggregate Weight (S) can be determined as follows; 441/ / / / S/ x 1000 = S + 25 = 1000 S = 245.4/ = 630 kg Note : In case of using Silica Fume, Admixture rate will increase to 2.5% of cement materials. Table No.(8) Mix component (kg) for 1m3 High performance Cnocrete Cement Fly Ash Silica Fume Slag Fine Agg.(kg) Coarse Agg.(kg) Water Admixture

29 Part (4): Testing and Quality Control 4-1 High Performance Concrete Tests Fresh Concrete Tests: To measure High Performance Concrete workability, the following tests are to be used: 1. Slump test 2. Slump Flow test Workability of fresh concrete shall be measured by slump flow, and its value shall not be less than 500mm Hardened Concrete Tests: Table No.(9) shows a summary for required tests to determine concrete performance which is required according to Saudi Arabia conditions. Table No.(9) Required tests to determine High Performance Concrete Grade Properties Standard Method of Test Remarks Abrasion resistance (avg. abrasion thickness mm) ASTM C944 Measuring abrasion depth according to test method(b) of ASTM 799 Chloride penetration resistance (Columbus). AASHTO T277 ASTM C1202 Check according to standard method of test Compressive strength (MPa) AASHTO T22 ASTM C39 Running the test at 7 days and 28 days 29

30 Quality Control of High Performance Concrete: The Contractor shall check the quality of high performance concrete work by carrying out all tests including in item , and with the frequencies shown in Table No. (10). The test results shall be compared with limits given in Table No. (11) for each grade of concrete. Table No. (10) Test rate for quality control of High Performance Concrete Properties Slump Flow test Abrasion resistance (avg. abrasion thickness mm) Chloride penetration resistance. Compressive strength Standard Method of Test Once per charge At the beginning of project, and once per month At the beginning of project, and once per month Once set per each 100 m3 Table No.(11) Different grades for High performance concrete Properties Standard Method of Test High performance concrete grades according to FHWA Abrasion resistance (avg. abrasion thickness in mm) ASTM C mm mm 0.5 mm Chloride penetration resistance (Columbus). AASHTO T277 ASTM C Compressive strength after 28 or 56 days (MPa) AASHTO T22 ASTM C MPa MPa MPa 97 MPa 30